8-Hy-droxy-5,7-dimethyl-quinolin-1-ium hydrogen sulfate

The quinoline ring system of the title salt, C11H12NO(+)·HSO4(-), is essentially planar, with a maximum deviation of 0.054 (2) Å for all non H atoms. In the crystal, the cations and anions are linked via N-H⋯O, O-H⋯O and weak C-H⋯O hydrogen bonds, and are stacked respectively in columns along the a axis. π-π stacking inter-actions, with centroid-centroid distances of 3.5473 (12) and 3.6926 (12) Å, are also observed. The crystal studied was an inversion twin with refined components of 0.43 (7):0.57 (7).